Glutamic acid, labelled

O Leary and coworkers measured rates at low substrate concentrations with ordinary glutamic acid, and also with glutamic acid labeled with in its carboxyl group. 

Radiolabeled folate provides a powerful tool for folate bioavaHabiUty studies in animals and for diagnostic procedures in humans. Deuteration at the 3- and 5-positions of the central benzene ring of foHc acid (31) was accompHshed by catalytic debromination (47,48) or acid-cataly2ed exchange reaction (49). Alternatively, deuterium-labeled fohc acid (32) was prepared by condensing pteroic acid with commercially available labeled glutamic acid (50). 

The first example of a dynamic flux analysis was a study performed in the 1960s [269]. In the yeast Candida utilis, the authors determined metabolic fluxes via the amino acid synthesis network by applying a pulse with 15N-labeled ammonia and chasing the label with unlabeled ammonia. Differential equations were then used to calculate the isotope abundance of intermediates in these pathways, with unknown rate values fitted to experimental data. In this way, the authors could show that only glutamic acid and glutamine-amide receive their nitrogen atoms directly from ammonia, to then pass it on to the other amino acids. 

Biological. Incubation of C-ring labeled endothall (10 mg/mL) by Arthwbactersp., which was isolated from pond water and a hydrosol, in aerobic sediment-water suspensions revealed that after 30 d, 40% evolved as CO2. Glutamic acid was the major transformation product. Minor products were alanine, citric, and aspartic acids and unidentified products, some of which were tentativeiy identified as phosphate esters (Sikka and Saxena, 1973). In pond water treated with endothall (2 and 4 ppm), detectable levels were found after 7 d (Sikka and Rice, 1973). Biodegradation was rapid in an Ontario soil sample. After 1 wk, 70% of endothall added was converted to carbon dioxide (Simsiman et al, 1976). 

After reaction of 6-14C-DON with glutaminase, glutamic acid (1 equivalent) and I4C-methanol (0.75 equivalent) were isolated from the reaction mixture. The initial product formed from the C-6 atom appears to be diazomethane Ha). If relatively high concentrations of a benzoic acid-benzoate buffer are included in the reaction mixture, labeled methyl benzoate is formed in addition to the methanol. Further, the relative... 

The discovery of D-glutamic acid cyclotransferase was foreshadowed by the observations of Ratner (23) who fed rats D,L-glutamate labeled with 15N in the amino group and deuterium attached to the a- and / -... 

Fig. 34.2. Electropherograms using (A) LIF and (B) EC for simultaneous dual detection. Detection of dopamine (DA 50 pM), catechol (CA 110 pM), and flu-orescently labelled arginine (Arg 140 pM), phenylalanine (Phe 180 pM), and glutamic acid (Glu 220 pM). Reprinted with permission from Ref. [46]. Copyright (2002) American Chemical Society.

The Wolff rearrangement and the Arndt-Eistert homologation sequence are very useful in organic synthesis. One of the most popular applications involves amino acids. An interesting example has been described as a key reaction in the synthesis of a 14C-labeled amino acid used for deciphering the biosynthesis of penicillin N from glutamic acid (Scheme 3.2).9 This rearrangement proceeds without racemization and can thus be applied in peptide synthesis. 

All data obtained with Tecan Ultra Evolution MTP reader. The following excitation and emission wavelengths were used EDANS and AMC 350 and 500 nm RhllO 485 and 535 nm TAMRA 535 and 595 nm PT14 405 and 450 nm. 4 = primary cleavage site confirmed by MS. AMC = aminomethylcoumarin. RhllO = rhodamine 110. yE = glutamic acid attached to RhllO via its carbonic acid in side chain. EDANS = fluorophore 5-[(2-aminoethyl)amino]naphthalene-l-sulphonic acid. DABCYL = 4-(4-dimethylaminophenylazo)benzoic acid quencher. BTN = biotin. PT14 = acridone-based fluorescence lifetime label. 

Takagaki, G., S.Berl, D.D.Clarke, D.P.Purpura, and H.Waelsch. 1961. Glutamic acid metabolism in brain and liver during infusion with ammonia labeled with nitrogen-15. Nature 189 326. 

An adapted soil bacterium identified as an Arthrobacter sp. incorporated most of the labeled carbon from dalapon-2-14C into various cellular components (amino acids, lipids, protein, and nucleic acids) while the carboxy carbon was accounted for mostly as 14C02 (2). Products identified on paper chromatograms were the amino acids alanine and glutamic acid (Figure 8). An enzyme preparation obtained from the supernatant fluid of broken cells of the same Arthrobacter sp. liberated Cl ion from dalapon to yield the organic acid pyruvate (31). The... 

Of particular importance to heterocyclic chemistry is the labeling of optically active amino acids. Preliminary results5 42 with methionine, proline, tryptophan, and glutamic acid show that significant racemization can occur even in the crystalline phase. In a systematic study of the... 

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